1. Field of the Invention
This invention relates to a fluid medicine delivery device, and, more particularly, the invention is directed to a microdispensing ophthalmic pump for delivering a microdose of ophthalmic fluid.
2. Description of the Prior Art
U.S. Pat. No. 5,152,435 (hereinafter "the '435 patent)", entitled "OPHTHALMIC DISPENSING PUMP", discloses a manually operated dispensing pump capable of delivering a precise quantity of ophthalmic solution to the surface of an eye in a desired spray pattern with an impact pressure on the eye that is comfortably tolerable by an individual and was issued to a co-inventor, Ben Z. Cohen, of this patent. The '435 patent is incorporated by reference herein, including the extensive discussion of the shortcomings of the prior art. The spray pump of the '435 patent is a substantial improvement over the prior art, capable of delivering doses of ophthalmic fluid such as 50 microliters in the previously described manner. However, often a dose of much less than 50 microliters of ophthalmic fluid may be required to be delivered in the manner described above. Since a reduction in the size of a dosage inherently decreases the impact force exerted by the dose onto an eye, the administration of fluid by the '435 patent would be even more comfortably tolerable than that disclosed therein with a reduction in the size of the dose the '435 pump could deliver. Also, some medications can have toxic effects, even at doses as small as 50 microliters, and so doses of less than 50 microliters would be better tolerated.
It is a primary object of the subject invention to provide a manually operated microdispensing pump for delivering a microdose of ophthalmic solution as small as 5 microliters.
Also, it is an object of the subject invention to provide a manually operated microdispensing pump capable of repeatedly administering a full and proper microdose as small as 5 microliters.